Role of GhHDA5 in H3K9 deacetylation and fiber initiation in Gossypium hirsutum |
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| Authors: | Verandra Kumar Babita Singh Sunil K. Singh Krishan M. Rai Surendra P. Singh Anshulika Sable Poonam Pant Gauri Saxena Samir V. Sawant |
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| Affiliation: | 1. Plant Molecular Biology Laboratory, National Botanical Research Institute, Lucknow, India;2. Department of Botany, University of Lucknow, Lucknow, India;3. Academy of Scientific and Innovative Research (AcSIR), CSIR‐NBRI, Lucknow, India |
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| Abstract: | Cotton fibers are single‐celled trichomes that initiate from the epidermal cells of the ovules at or before anthesis. Here, we identified that the histone deacetylase (HDAC ) activity is essential for proper cotton fiber initiation. We further identified 15 HDAC s homoeologs in each of the A‐ and D‐subgenomes of Gossypium hirsutum . Few of these HDAC homoeologs expressed preferentially during the early stages of fiber development [?1, 0 and 6 days post‐anthesis (DPA )]. Among them, GhHDA 5 expressed significantly at the time of fiber initiation (?1 and 0 DPA). The in vitro assay for HDAC activity indicated that GhHDA 5 primarily deacetylates H3K9 acetylation marks. Moreover, the reduced expression of GhHDA 5 also suppresses fiber initiation and lint yield in the RNA interference (RNA i) lines. The 0 DPA ovules of GhHDA 5 RNA i lines also showed alterations in reactive oxygen species homeostasis and elevated autophagic cell death in the developing fibers. The differentially expressed genes (DEG s) identified through RNA ‐seq of RNA i line (DEP 12) and their pathway analysis showed that GhHDA 5 modulates expression of many stress and development‐related genes involved in fiber development. The reduced expression of GhHDA 5 in the RNA i lines also resulted in H3K9 hyper‐acetylation on the promoter region of few DEG s assessed by chromatin immunoprecipitation assay. The positively co‐expressed genes with GhHDA 5 showed cumulative higher expression during fiber initiation, and gene ontology annotation suggests their involvement in fiber development. Furthermore, the predicted protein interaction network in the positively co‐expressed genes indicates HDA 5 modulates fiber initiation‐specific gene expression through a complex involving reported repressors. |
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| Keywords: | cotton fiber initiation GhHDA5
Gossypium hirsutum
trichostatin A in vitro histone deacetylase assay reactive oxygen species epigenetics |
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